


The Rule of Three

by elise_509



Category: Marvel Cinematic Universe, The Avengers (2012)
Genre: M/M
Language: English
Status: Completed
Published: 2012-08-13
Updated: 2012-12-30
Packaged: 2017-11-12 02:13:37
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 3
Words: 13,157
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/485544
Author URL: https://archiveofourown.org/users/elise_509/pseuds/elise_509
Summary: <blockquote class="userstuff">
              <p>Steve likes Bruce in a way he doesn’t like Tony.  It’s all warm and smooth between those two.  They’re the kind of friends who can sit for hours and probably not say a word to one another and call it a great day.  </p><p>Tony knows it’s the exact opposite with him and Steve.  He fires Steve up; it’s all heat and tension, sharp edges rubbing against sharp edges.</p><p>Eventually the sharp edges get worn down and they fit together like they were made to be that way.  And then they find new ways to create friction.</p>
            </blockquote>





	1. Tony

**Author's Note:**

> PWP. Not one single ounce of plot here!

Steve unbuttons his shirt slowly, but it’s not for dramatic effect. Although his hands are steady Tony can recognize nervousness in Steve’s down turned gaze. And while the sight of his long dark eyelashes fluttering against his flushed cheeks makes for an enticing picture, Tony knows that if Steve were sure about this, the man would be looking him straight in the eyes. 

He’s about to tell Steve that he should stop if he wants to. Despite how Tony very much likes the sharp cut of muscle being revealed – god, he’s never been so _aware_ of desperately wanting to _lick_ someone before, that vee leading from Steve’s hips down into his jeans is just _begging_ for his tongue to follow it – he’s not about to let Steve get into something he’s not ready for simply because the man’s as stubborn as a mule. 

Tony opens his mouth to say as much when Bruce steps up silently behind Steve, placing his hands around Steve’s waist. His thumbs brush gently against Steve’s skin, small circles just inside the open flaps of his shirt. 

Bruce’s touch reassures Steve, somehow; he stills as Bruce gently pulls the loose fabric of his light blue button-down from where it rests on his broad shoulders. Steve tilts his head slightly to the side to look at Bruce over his shoulder. Bruce doesn’t meet his glance; rather shy for a man who is helping Steve undress. 

Bruce actually folds Steve’s shirt carefully and sets it aside on Tony’s desk chair. It’s amazing how cautious and gentle Bruce is when the Other Guy is anything but. Two sides of a coin are still opposites, even if they are inescapably part of the same thing. 

A hint of a smile tugs at the right corner of Steve’s mouth as Bruce finishes with the shirt. Steve likes Bruce in a way he doesn’t like Tony. It’s all warm and smooth between those two. They’re the kind of friends who can sit for hours and probably not say a word to one another and call it a great day. 

Tony knows it’s the exact opposite with him and Steve. He fires Steve up; it’s all heat and tension, sharp edges rubbing against sharp edges.

Eventually the sharp edges get worn down and they fit together like they were made to be that way. And then they find new ways to create friction. 

Maybe that’s what this is, Captain America standing half-naked and utterly beautiful in the middle of his bedroom on a Thursday night. 

A new way to create friction. 

Steve looks at him then. 

It’s not exactly a come hither stare but the look is definitely an invitation to action; it’s Steve saying _here I am_ and Tony being unable to resist when Steve is just _right there_.

Tony moves toward him without thinking.

He jostles Steve’s body forward slightly when his hands land and pull on Steve’s belt buckle, deftly working the leather and metal without dropping his gaze from Steve’s. His eyes are impossibly blue and honestly, one of Tony’s favorite things about him. Maybe because they’re one part of Steve that would’ve been the same before he changed into America’s favorite super soldier, something that couldn’t be bettered because you can’t upgrade perfection. He’s seen the photos and even in black and white, even in that scrawny, sickly little body, Steve had a gorgeous gaze. 

Steve’s lids drop closed for a moment as Tony unzips him, cups his palm against the front of Steve’s tented black boxer briefs. Having someone so warm and hard and aroused underneath his hand is not a new sensation, but it thrills him like the very first time because it’s _Steve_ and he still can’t quite believe this is happening. Steve exhales a soft gasp and Tony has to take advantage of those slightly parted lips. He lunges up to capture Steve’s mouth before he thinks better of it.

Kissing Steve seems more daring and intimate than rubbing his hand over Steve’s growing erection, but he wonders which action surprised Steve more. Which action makes Steve whimper deliciously against his lips and sink that much further into this. 

He feels rather than sees Bruce step in close beside them, too occupied with Steve’s mouth to register more than additional body heat and the press of Bruce’s linen shirt against his own bare arms. Another hand slides into Steve’s jeans beside Tony’s, but he only feels it as a shifting shape underneath cotton. Bruce apparently couldn’t wait and has slipped his hand beneath Steve’s underwear, wrapping his fingers around bare flesh. 

Steve’s breath stutters across Tony’s lips.

“Impatient hussy,” Tony mutters at Bruce as he breaks from Steve’s kiss. Bruce smiles at the tease and withdraws slowly, stepping away and leaving Steve to rock his hips into nothing but air. His eyes flutter open and before Steve can feel bereft or embarrassed, Tony looks him up and down and snaps his fingers.

“Clothes. Off. Now. All of it.” He gestures for Steve to get a move on and Bruce chuckles.

“And I’m the impatient one.” 

“Chop chop, Cap,” Tony ignores Bruce. Steve blushes but hooks his thumbs under his jeans and underwear and pushes them down his legs. 

Tony tries desperately to think of something witty to say but it all sounds like bad porn. Which hardly matters because he can’t speak when he’s nearly swallowing his tongue. 

Steve shifts uneasily on his feet, shoving his clothes side with a shuffle of a kick. 

“Tony, I-“ He’s surely about to say something about being the only one naked in the room, or maybe he’s about to mention that both Tony and Bruce are staring at him like they’ve forgotten the English language, but he’s clearly embarrassed and that’s enough to spur Tony on. 

He closes the space between them and kisses Steve again, sliding a hand around and over Steve’s waist to feel how firm Steve’s ass is as he does so. It’s tight and muscled just like every other inch of him and Tony gets his other hand around and squeezes, urging Steve closer against him. 

Steve goes with it easily, his tongue sliding along Tony’s and his strong arms encircling Tony’s body, lifting him up onto tiptoe to kiss him more deeply. Steve makes exquisite little noises as Tony rubs against him, denim and cotton and metal brushing against naked skin. 

Tony has the sudden realization that he’s going to come in his pants. It’s going to happen in approximately 2.2 seconds if he doesn’t pull away from Steve immediately.

He rips himself back, physically shuddering as his body decries his mind’s decision not to fulfill its desire. 

“Fuck.” Tony mumbles as he stares at Steve from a few safe feet away. Bruce at least has the mental capacity left to register the look of concern that appears on Steve’s face. 

“It’s fine, he’s fine,” Bruce assures Steve, setting one hand on Steve’s shoulder as he lifts the other to the side of Steve’s face. The backs of his fingers trace Steve’s jaw line tenderly. “Just trying not to get carried away, that’s all.” 

“Okay,” Steve replies quietly, his voice shaky. 

“You do realize that you’ve chosen to be with the two people who have the least amount of self control in this tower. In this city. Perhaps the planet.” Tony rambles out. “Universe? Maybe universe is going too far. Knowing Asgard exists now, who knows what else is out there, right? If Thor’s anything to go by, there could be some other contenders in the far reaches of the galaxy.” 

“Maybe if you guys…” Steve stops, rubs the back of his neck. “I mean, maybe if we were all undressed?” 

“Uh, no,” Tony shakes his head even as Bruce starts unbuttoning his own dark blue shirt. He gestures to his own jeans and black tank. “These are quite possibly the only things keeping me from throwing you down on the ground and ravishing you like the cover of some harlequin gay romance.” 

“I thought that was kind of the point.” Steve replies and Tony stares at him, a bit surprised. He hadn’t really been expecting for Steve’s forthright and rather blunt demeanor to show up inside the bedroom. He’d been expecting some blushing, maybe a little hand-wringing, and a lot of time spent trying to draw Steve out of his shell. Figuratively. 

They’d gotten him naked really fast.

Bruce ducks his head, hiding a small smile. He finishes taking his own shirt off and sets it less carefully on top of Steve’s. 

“What Tony means is that tonight’s supposed to be about you.” He places his hand on Steve’s hip and his tan fingers against Steve’s pale skin are a delicious contrast. “That’s what we agreed, anyway.”

“You two talked about this?”

“These two highly analytical minds and you think we _didn’t_ discuss how it was going to go when we brought Captain America into a three-way?” Tony moves closer to the pair, confident that he has his libido under sufficient control to touch Steve again. “We talked about it. Talked about it in this here bed quite a few times, actually.” 

He backs Steve toward said bed, smiling as Steve’s eyebrows lift in surprise. 

“Yeah, you’ve been responsible for a few orgasms between me and Brucie without y’know, being here. I can tell you in explicit detail exactly what Bruce wants to do to you with his tongue, if you’d like.” 

Bruce is already sitting up against the headboard, idly fingering the button of his trousers, and he shoots Tony a warning look. 

“How about we don’t overwhelm the poor guy the first time?” He admonishes Tony, who shrugs and gently pushes Steve backward by the shoulders until he gets the drift and shifts onto the bed. Bruce spreads his legs and urges Steve to lie back into his embrace. 

“This shouldn’t be all about me,” Steve protests softly. Bruce responds by sliding his arms under Steve’s and around his body, fingers splayed over his broad chest. 

“It’s how we’d like it to be, if that’s okay. This once.” His lips brush the side of Steve’s face as Steve leans his head back onto Bruce’s shoulder. Steve relaxes a little, closing his eyes and focusing on the sensation of Bruce’s gentle kiss. 

Tony crawls onto the foot of the bed, memorizing the sight of Captain America, star of many an adolescent wet dream, spread out on his king size bed. How many nights had he spent imagining coming all over that tight blue uniform? And that’s not even as hot as the image of Steve Rogers, featured player in his most recent fantasies, being held in Bruce’s arms, naked and ready and waiting for them both to use him all night long. Perfect, solid Steve who was so much better a man than Tony had ever dreamed Captain America could be. 

He leans in, running his hands up the insides of Steve’s thighs. Steve opens his eyes, watching as Tony dips his head and licks a hot, wet line up the underside of his hard cock, tracing the vein and feeling his whole length twitch. Tony draws back the skin of the uncut tip and presses his lips to the sensitive head. Steve’s body arches away from Bruce’s, pushing toward the incredible feeling of Tony’s tongue. 

Tony repeats the motion, gathering the drop of liquid that pearls from the slit. 

“Oh…” Steve sighs shakily as Bruce tightens his hold, keeping Steve steady. Tony rubs his thumbs along the lines where hip meets thigh, his blunt nails brushing the delicate skin at the base of Steve’s erection. 

Tony is used to talking during sex – loud, noisy, filthy, playful – but now he finds that he’s liking the quiet. He likes the hum of tension between the three of them, the way he can practically hear the taut line of Steve’s beautiful body pulling tighter, the way Bruce’s breathing has gone all ragged and rough. It might be more fun if he said something cheeky and made Steve laugh against his will, if he gave Bruce something to shush him for, but he doesn’t really want fun. He wants to feel every second and remember every second and have every second build and build until they all can’t take it anymore. 

He wants to break Steve apart and let that break him in turn. He wants Bruce to see it, to watch them all crumble and put each other back together again. 

It’s different from wanting it rough. He’s had it rough. He doesn’t want to dominate or be dominated. He’s probably had sex in every way possible, hit every kink, tried every style and every position, but he’s never had this. And he kinda just wants it to last for as long as it can possibly last. 

He works his mouth down Steve’s length, taking his time. He rubs and strokes everywhere his tongue can’t reach, Steve’s cock impressive enough that he can’t quite take it all. Steve’s breathing grows quicker, each exhale more pronounced. Bruce’s hands are moving over Steve’s chest and stomach, taking in the flex and shift of muscles under skin. 

Bruce has always loved the biology of sex. Watching Steve react to what Tony’s doing already has blown his pupils wide and dark. His face is flushed and there’s a small tremor wavering along his usually dexterous fingers. 

Tony drags his mouth from Steve’s dick and reaches for one of Bruce’s hands. He folds Bruce’s grasp around where his lips had just been and encourages Bruce along, stroking Steve together for a beat. 

Steve shifts into their combined grasp and gasps out something unintelligible. He arches his neck, head pressing further back onto Bruce’s shoulder and Bruce takes his other hand and tilts Steve’s chin even more, taking Steve’s mouth in a hot, open-mouthed kiss. Steve moans into it and the sound of it reverberates straight to Tony’s groin. 

“Fuck,” he mumbles to himself and hooks his hands under Steve’s thighs, spreading his legs further apart. Then he bends forward to take Steve’s balls gently in his mouth, rolling their heavy weight gently over the flat of his tongue. Steve almost bolts upright, stuttering out a groan and tensing up. Bruce holds him back but lets Steve reach out and fist a hand in Tony’s hair. 

“God, Tony…” Steve whispers, holding Tony where he is and rocking into it as Tony dips lower, tongue lapping over and around his entrance. “Bruce, oh god…He’s…his tongue… _fuck_ …” Steve sounds disbelieving, as if nothing like this could really be happening to him. 

Tony looks up the length of Steve’s body, fucking inside with his tongue as Bruce continues working Steve’s cock, which is thick and dark and leaking back onto his flat stomach. Bruce is shifting his hips against Steve’s backside, the motion nearly aborted in the restricted space. But apparently between his clothes and the closeness of Steve’s ass to his erection, there’s enough friction for Bruce to gain his own pleasure. 

“Bruce, are you gonna come? Gonna come just from this?” Tony chokes out, his throat dry and raw already. “Unzip. Come all over his back. Mess him up.”

“Tony…” The moan is doubled, sudden surround sound of frustration and desperation. Steve arches and Bruce shoves his hand underneath Steve into the small space between their bodies. They both look awkward and uncomfortable for a moment until Bruce gets his zipper open. Tony can’t see but he must get his dick free because Bruce sighs with relief and Steve settles back down against him. 

Tony sits back on his heels and watches as Bruce nestles his hard-on against the small of Steve’s back and takes hold of Steve’s sharp hips. Steve’s whole body ripples with pleasure as Bruce pushes up against him. 

And with that goes the last remnant of Tony’s resistance. 

Fumbling with his fly, he gets his cock out with absolutely no finesse, shoving his clothes down just enough to relieve the unbearable pressure. 

He takes out the lube from the bedside table and coats his fingers with it, not caring as it drips all over the bedspread, over Steve’s legs, down his own wrist. He plans to make a mess of this bed before the night’s over, have Steve and Bruce ruin the sheets with sweat and come until they have no choice but to just throw the hopelessly destroyed linens out in the morning. 

He presses his middle and index finger against Steve’s entrance.

His hesitation asks the question for him and Steve nods.

“Yeah, yes, do it. Please.” 

Tony slides his two fingers inside. Steve’s warm and tight, so tight. His cock throbs with need, and Tony curses his impatience. He wants to thrust deep inside Steve right now and knows that he can’t. Shouldn’t. 

“God, are you…?” Bruce lifts his head higher, craning to see Tony’s hand moving between Steve’s thighs. Steve starts softly rocking his hips down to meet Tony’s gentle fingers, rocking back against Bruce’s arousal. Bruce drops his head back against the pillows and pulls Steve tighter to him, then lifts his head again to look, like he can’t stop himself from doing so. 

Tony moves his hand deeper, stroking and scissoring, stretching Steve a little at a time. He trains his gaze on Steve’s face for a moment, reading his reaction, and then shifts to check in with Bruce. They exchange a long look; Tony remembers three nights ago when he’d been doing this to Bruce, Bruce coming on his hand as he mouthed off about how, for the good of science, they should take Steve to the lab and drive him to orgasm after orgasm, to see how sexual stimulation affected a successfully super serum-enhanced body. 

Of course, Bruce had countered with his own ideas on how to test the full breadth of Steve’s stamina, and they’d both wound up, in the afterglow, deciding that it might finally be time to act on their shared desire before they went nuts and demanded to attach electrodes to Steve and watch him masturbate. 

Though that’s not really a bad idea, sans electrodes. 

“Touch yourself,” He tells Steve, though it sounds a bit more like he’s begging. Steve’s fingers are twisting in the bedspread on either side of his body. Tony strokes a finger over that spot he knows will send Steve spiraling, watches with satisfaction as Steve’s eyes roll back into his head and his entire body wracks with pleasure. 

“Touch yourself,” Tony pleads once more, slipping a third finger in alongside the first two. Steve does move a hand this time, but only to grab Tony by the hip. 

“Inside…get inside me, Tony. Now. God, right now. _Please._ ” 

Steve’s obviously much, much better at the whole begging thing than he is. 

“Turn over,” Tony instructs him but Steve shakes his head. “Steve, it’ll be easier on you if you’re-“

“Don’t want easy. Want it like this,” Steve replies, breathless and sounding more Brooklyn than he ever has. Tony likes his accent slipping back, knows they’ve stripped Steve down somehow, back to the base of who he really is. 

“Do it like this, Tony,” Bruce nods raptly. His loose, dark curls are stuck to his forehead with sweat, his brown eyes glazed. Tony fumbles for the lube again, liberally coating himself and stroking a few times to spread it and warm it up. 

Bruce wraps one arm firmly around Steve’s waist, holding him steady with a palm flat on Steve’s chiseled stomach, while the other hand strokes through Steve’s hair. Tony sets his left hand beside Bruce’s on Steve’s body, uses the other to line himself up. 

Steve tenses and hisses slightly as Tony breaches him, pushing the head of his cock just inside. It takes every last reserve of will power for Tony not to shove home. He holds his breath, wraps fingers around his base and pinches tight, trying to keep from exploding between Steve’s muscular thighs. 

“Okay?” Bruce murmurs against Steve’s ear and Steve nods. “Can you say it, Steve?”

“I’m okay.” Tony feels Steve start to relax underneath him and around him. “I’m okay.” Steve says directly to Tony this time, and damn, those eyes again. They’re going to be his undoing. 

Tony locks into his stare as he pushes all the way in, painstakingly slow. He can read every minute reaction on Steve’s face, holding still when he’s finally buried deep, waiting until the pain recedes and pleasure takes over. 

It doesn’t take long at all before Steve bites his bottom lip and moves experimentally, clenching around Tony as he does so. Tony swears sharply and Steve stops, alarmed.

“No, that was a good _fuck_ , Steve. A way too good _fuck_. Do that thing with your hips again and I’m done for.”

Steve manages to lift an eyebrow and give him a small half-smile and Tony decides that, just like with everything else, Steve is a natural at this whole sex thing too. 

Gradually, Tony builds up into a rhythm, Steve’s body turning welcoming and then downright desperate, Steve spreading his legs further and letting Tony push deeper. Every thrust rocks and rubs Steve back against Bruce, who is alternately sucking a dark bruise onto Steve’s neck and kissing Steve’s mouth, tongue thrusting and sliding in a perfect mimicry of what Tony’s doing below. His strong hands roam freely, occasionally brushing Tony’s as they map Steve’s body together. 

Tony hitches one of Steve’s legs up, fingers grazing Bruce’s thigh as he does so. Just like him, Bruce still has his pants on, and Tony wonders how this has to feel for Steve, zippers and belt buckles and denim and cotton-polyester blend rubbing and biting and scratching his sensitive skin as two men basically fuck him from the front and the back. 

With belated thoughtfulness, Tony grabs his jangling buckle and pulls his belt free from his jeans, whipping it loose and tossing it onto the floor. 

“Not gonna to tie me up?” Steve asks, causing Tony’s hips to stutter. Tony makes up for the disruption in the rhythm by thrusting deep, making Steve grunt. 

“Maybe next time, cowboy,” he jokingly promises, figuring Steve would really never. But he doesn’t think he imagines how Steve’s eyes spark at his words. He definitely doesn’t imagine Bruce suddenly digging his nails sharply into Steve’s skin and groaning into Steve’s neck, his body tensing and going still except for the sharp stab of his hips as he comes. 

“I think Bruce likes the idea,” Tony comments. He considers turning Steve over so he can slip-slide his hands over Steve’s come-slick back and pound into him, make him spill all over Bruce and get them both good and dirty, but he selfishly wants to see Steve’s face when he lets go. 

He should’ve learned his lesson by now, that being selfish comes to no good, because he doesn’t wind up getting to watch. 

Steve murmurs, “Come inside me, Tony, want to feel you,” in this breathy, utterly filthy tone that somehow manages to sound earnest and loving anyway. And as the words trip off Steve’s tongue, words Tony never imagined the man could or would say, Tony does as commanded and empties deep inside Steve’s body. 

He was always pretty sure he was a hell-bound man, but for a minute he thinks differently. Whatever god there is – because in moments like these he’s pretty sure there is one – Tony’s gotta be in his or her good books if he’s allowed to feel something as awesome as this. 

The last thing he thinks before blacking out with bliss is that bringing Steve Rogers into his and Bruce’s bed was the best idea he’s ever had. All things considered, that’s saying a lot.


	2. Bruce

**Summary for the Chapter:**

> Maybe they’re just fluid like water, three atoms joining to make the most basic and necessary of all things. On their own they could be dangerous, on their own they could drift away, so maybe he and Tony need Steve to make them stable, make them whole.

Tony stirs slightly but doesn’t wake as Bruce gently helps Steve push Tony off of him to the free space beside him on the bed. Steve whimpers, shivering as Tony’s spent cock slips from inside his body. 

Bruce lets his hand ghost over Steve’s ignored erection, feeling the full length twitch and pulse underneath the pads of his fingers. 

He’s too turned on to be truly disappointed in Tony or in himself for getting ahead of themselves and leaving Steve wanting. They’d planned on focusing on Steve, but they hadn’t really counted on how difficult it would be to keep their own lust at bay for long enough to make that a reality.

“Tony okay?” Steve whispers even as Bruce’s touch drifts lower, brushing intimately between his legs where Tony’s come has left him dripping wet. 

“Tony’s fine. You okay?” 

Steve nods but Bruce can feel his whole body trembling against his own. He needs to see Steve’s face, look into his eyes and make sure he’s really all right. 

“Turn over.” Steve doesn’t move at first so Bruce asks him again. “Steve, please.”

Steve shifts down as he sits up, and then carefully turns himself over so he’s facing Bruce. It’s strange how relieved he feels to finally have Steve meet his gaze, to be able to look him over fully. If they do this again – share Steve, share each other – he wants to have Steve just like this, in front of him the whole time. He’s beautiful, and even if a small part of him wants to destroy that, a larger part wishes only to protect it. 

Steve’s hair is mussed, his whole body flushed with heat. His lips are used and his skin’s written with the history of the evening. It gives Bruce no small thrill to know that he and Tony have done this to him. Steve’s eyes are still dark with want but he looks frightfully unsure, his body so clearly aching for release but his mind aware that his own pleasure had been abruptly abandoned when Tony fainted into oblivion. 

“Come here,” Bruce raises himself onto his elbows, reaches out and slides a hand behind Steve’s head and guides him down into a kiss. He licks into Steve’s mouth, drawing him closer, wordlessly prompting Steve to lay his weight down against him. 

His teeth gently tug at Steve’s bottom lip, pulling a gasp out from him as Steve’s hard cock slips against the mess of come on his stomach. Bruce slides his hands through the matching splatter on Steve’s lower back, traveling downward until he has his fingers splayed wide over both sides of Steve’s ass. He squeezes, pushes down, urging Steve to rut against him. It's amazing when he starts moving.

Steve’s body is like an immaculately designed machine, each part perfect in proportion and function. It makes his own body feel right, makes his own mind clear. He’d been afraid of sex for so long after his accident, but with Tony, now with Steve, it’s pretty much the only time the other guy gets quiet, calm, stops pulling at the ragged seams of his psyche. 

He figures sex is one of the more animalistic pursuits that humans pursue; the base instinct of it all, the id seeking out pleasure, the innate need to mate. The other guy has no qualms with it. He doesn’t need to come out for this because, he, Bruce, instead comes to him. 

Sex is his equalizer. It turns off the noises in his brain and allows him to feel everything so vividly, maybe even moreso than he did before the other guy arrived. He revels in how soft and warm Steve’s skin is, how he smells like soap and mint and the faint tang of sweat. How Steve’s plush, bitable lips brush against his own, his voice broken and pleading as he whispers out his desire. 

“Let me?” Bruce murmurs back, finger circling around Steve’s entrance with increasing pressure. Steve nods and kisses Bruce feverishly, sloppy and deep. His groan echoes down Bruce’s throat, vibrating against his lips, as Bruce pushes a finger inside. He’s still open and slick from Tony having him and Bruce considers halting the path they’re on, instead taking a detour so he can part Steve with his tongue, lick him out. 

He’s about to ask Steve if that’s something he might want, pulling out of their kiss, when Tony comes to beside them. He lifts his head from his pillow with a confused frown. That expression quickly clears and changes as he takes in the sight before him. 

“Fuck, what did I miss?” He asks, and Bruce strokes deeper, pushes his hips up against Steve to meet his full body shudder. 

"That." Bruce replies.

“So fucking hot,” Tony breathes, words raw and desperate already. Steve turns his head and Tony surges forward, devours Steve’s mouth. Tony blindly fumbles for Bruce, getting a hand behind his head and lifting up so he can move right from Steve’s lips to Bruce’s. 

“Did he come?” Tony asks him but Steve answers.

“Waiting for you,” he gasps and Tony’s hand tightens in his hair. 

They’re both in trouble. He wonders if Tony realizes just how much. They’re never going to be able to let this go. 

Then Tony’s finger is sliding beside his, pushing in and out and sending Steve keening. 

“Let it go, Steve, let it go,” Bruce urges, feeling Steve’s body tensing in a bad way, fighting his own pleasure. 

“Come for us, baby,” Tony says in a gentle tone that Bruce has never quite heard before, and then stills his finger inside Steve’s body, pressing rather than stroking. Steve pulls back from both their mouths and wraps a hand around his own cock, brings himself off harshly with three punishing jerks of his fist. 

He’s silent until he finishes pulsing, his come splashing hot and sticky over Bruce’s chest, even his neck. Then his body sags, a soft, disappointed-sounding swear pushing past his lips. He closes his eyes and doesn’t re-open them. 

“Hey,” Tony says, reaching up and easing Steve down between himself and Bruce on the bed. They both curl around Steve’s body, glancing at one another over the broad expanse of Steve’s heaving chest. Bruce knows something has gone wrong, somewhere, and that Tony clearly senses it too means it’s probably something big. 

Steve’s eyes are still tightly shut and in a surprising gesture, Tony leans over, presses a light kiss first to one and then the other, stroking a hand through Steve’s hair the whole time. 

“Steve…” Bruce begins, and Steve brings both his hands up to cover his face. Bruce lets him hide for a moment, then delicately pries one hand away. “Steve.” He tries again. 

“Sorry for ruining things. I just…I didn’t want to come.”

Those familiar feelings of unsettling panic and fear start creeping back in on him, wondering how he missed the signs leading up to now that Steve was having doubts. 

“Steve, if we made you do something you didn’t want to-“ 

“Didn’t want this to be over.” Steve interrupts and Bruce stops, worry receding slightly and turning into a calmer kind of concern. Steve sits up, but Tony grabs his shoulder and shoves him back down. He climbs on top of Steve, straddling his waist.

“Hey. Who said anything about this being over?” 

Steve’s face goes slack with surprise.

“What?”

“I was planning on keeping this up until you get so sick of us, you’d be begging for a night alone in your own bed. Wasn’t that the plan, Bruce?” 

“No one wants this to be a one time deal, Steve,” Bruce assures him. He faults himself for not telling Steve that before now; it’s something they should have been clear about from the start. “In fact, I was worried you might be the one who wouldn’t want this again.”

“Want this as long as I can have it,” Steve replies and before Tony can do it, Bruce kisses Steve. And then Tony’s kissing Steve, and then Tony’s kissing him, and the next half hour, maybe an hour, maybe half the night, passes by in a blur of arms and legs and mouths. They’re one continuous tangle on the bed, like molecules rearranging themselves into a series of patterns, building new elements. 

Or maybe it’s not even that complicated. Maybe they’re just fluid like water, three atoms joining to make the most basic and necessary of all things. On their own they could be dangerous, on their own they could drift away, so maybe he and Tony need Steve to make them stable, make them whole. 

Steve’s their oxygen and Bruce breathes him in, takes him deep and holds him there. 

He’s inside Steve before he realizes it, Steve rolling on top of him and sinking down, his body arching beautifully as he does so. Bruce is hazy as to how they got here, with Tony wrapping his arms around Steve from behind, holding Steve’s cut hips and kissing his neck, helping to guide Steve’s slow up and down motion. 

“That’s it, baby, ride him. Just like that.” Tony is mimicking Steve’s motions behind him, plastering himself against Steve’s back and sucking a deep, purple bruise at his collarbone. His hands grip Steve’s body, fingers digging in and leaving marks. Maybe he shouldn’t, but Bruce covers Tony’s hands with his own and presses harder. 

“Bruce…feels so good…” Steve picks up his pace, lost to the sensation in a way he wasn’t the first time around. 

“You’re both amazing,” Bruce shoves himself up, teeth clacking against Steve’s as they kiss messily. He can’t stay up like this and he falls backward, bringing Steve with him. He feels Tony move, grab his knees and bend his legs upward, planting his feet flat against the bed. Bruce lets himself be arranged. The new position gives him leverage to thrust up into Steve, his own hips doing the work while Steve rides it out. 

Steve leans forward, grabs the headboard, and lets Bruce fuck up into him. 

And then, there’s Tony’s tongue.

Steve loses control as Tony licks at the place their bodies join, this time needing no prompting to spill. Bruce follows immediately after, helpless against the clench of Steve’s muscles around him. 

He keeps moving, chasing every last vestige of his orgasm, until he feels Steve start to pull off. Tony’s arms are around Steve again and Steve half-moves, Tony half-lifts, until Bruce slides out and Tony slides in. 

Steve makes helpless, fucked out noises as Tony takes him with slow, sure, deliberate thrusts. Bruce can’t look away as Steve, relaxed and sated, lets Tony use his body completely. It has to be a sensory overload, and Bruce tries to find his voice, wondering if maybe he should tell Tony this might be too much. 

“So good, baby, almost there,” Tony murmurs, and Steve twists his head back, kisses Tony with everything he has left. Tony chokes out a groan and thrusts hard, one, two, three times and then stills. 

As Tony cradles Steve back against him, too wiped to do anything but hold each other, Bruce smiles goofily. 

This is what happy feels like. He’d almost forgotten.

“You okay there?” Tony checks as he and Steve lay down beside him, their bodies drawing back close together like magnets. Bruce lets himself be pulled. 

“I’m great,” Bruce replies, and he means it for the first time in years. Tony has his face muffled against Steve’s chest so he reaches over blindly, ruffles Bruce's hair. Bruce considers leaving the contented silence undisturbed, but before he forgets, he's tempted to point out the one thing Tony did tonight that was both amusing and strange. “Hey. How come you never call _me_ baby?”

Both Tony and Steve lift their heads, look at him. Steve tenses. Tony shoots him a look like he’s grown two heads. 

“Um…do you _want_ me to?” Tony asks, skeptical. 

“No. Not at all.” 

“There you go.”

Tony settles his head back down against Steve and throws his arm across the both their bodies, closes his eyes. After a moment, Steve relaxes. He takes Bruce’s hand in his and places it over Tony’s. 

“You can call me baby if you wanna,” Steve murmurs drowsily. Tony snorts out a chuckle and tugs them both closer. 

Bruce nestles his face against Steve’s hair, breathes him in, and drifts off to sleep.


	3. Steve

**Summary for the Chapter:**

> Steve loves the way both Bruce and Tony _look_ against his body - the contrast of color and shape, the ways they differ from him and are similar to each other…he just wants to study it. Wants to lay them out on the bed and draw them until he understands every line and shadow that constructs their form. And then have them come together just so he can watch them move, see the lines blur and shift.

He wakes with a start. 

Not the kind of violent start that sends him shooting upright in bed, his heart pounding in panic, but the kind that simply has him asleep one moment and completely wide awake the next with no semi-pleasant warm and drowsy state of in-between. 

Steve quickly inventories his surroundings, immediately aware that this isn’t his room just from the way the sunlight plays across the ceiling. The shadows shift differently, the shapes strange and unfamiliar. He’s not wearing a scrap of clothing and the bed sheets feel different against his bare skin – cool silk rather than warm flannel. Their color is deep wine red. 

Tony. Steve tilts his head to one side, expecting to find himself alone. He relaxes back into the pillow as he takes in the sight of Tony silent and still in slumber. He’s beautiful, and very much close enough to touch. Without thinking, Steve reaches out to stroke his hand through Tony’s soft, dark hair. Halfway through the motion he stops, suddenly unsure, and draws back. 

He recalls falling asleep the night before wrapped in both Tony and Bruce’s embrace, but during the night they’ve drifted apart. The bed’s big enough that even with all three of them, there's plenty of space between them. He doesn’t know how the two usually sleep, but he’d hate to think that these arrangements are due to his position in the middle, keeping them apart. He drops his hand and slowly turns over to his other side. 

Bruce is sleeping soundly, his breathing deep and even. He looks younger in sleep despite the way the morning light strikes his grey-streaked curls and the tinge of silver stippled along his stubbled jaw line. He seems less troubled too, none of that anxiety furrowing his brow as usual. Steve doesn’t know why he’s surprised they’re both still here; this is _their_ bedroom. He should hardly expect one of them to have left. But with Tony’s penchant for abandoning sleep for work and Bruce’s early morning meditations, he half-supposed he’d wake up alone, though he’s only really realizing just now that he’d supposed anything at all. 

Steve rolls onto his back carefully and lies still, entirely at a loss as to what to do. He takes a few measured breaths, folding his hands over his chest for a moment before shifting to lay his arms down along his sides. He should probably leave. That’d be the right call to make. 

He counts to ten, plotting the best way to extract himself without waking both Bruce and Tony. Given the considerable shift moving his weight will cause and seeing as how he’s smack in between the both of them, there’s really no tactical way to do this. So he just sits up and starts to move toward the end of the bed, accepting that he’s probably going to wake up one or the both of them. He’ll just have to keep moving, grab his clothes and make his way to the door as quickly as he can. 

If they give him even a weak excuse to stay, he’ll never be able to make himself go. 

Steve’s near the foot of the bed when Tony sits up, wraps an arm around his waist, and pulls him back down to the mattress. Steve reflexively tenses and has to stop himself from fighting Tony off, Tony's embrace startling him even though he knew Tony might stir.

“I’m gonna take a shower,” Tony murmurs drowsily, his words muffled by his pillow. He lifts his head back up a little to be heard properly. “Unless you’re planning on coming with me, you should stay here in bed.”

“Tony, I –”

“The shower’s big enough for the two of us. But the bed is comfy too, and you do look so good in it.”

“I should really go –”

“Shower it is then.” Tony grabs Steve’s hand as he drags himself from bed, blinking rapidly to clear sleep from his eyes. He’s moving slowly but he’s insistent, pulling hard on Steve’s arm. Steve resists and Tony lets out a frustrated sigh before turning to face him. Tony bends forward, cupping his jaw with one hand before kissing him firmly, forcing his mouth open and taking it deep. 

“Now.” Steve looks up at him as Tony draws back and gives him the once over, clearly more awake now than moments before. “I’m gonna go get some mouthwash or something because even though you don’t have morning breath – which is completely obnoxious, by the way – I’m sure that whole kissing thing just now was less than pleasant on your end. We did, however, make an absolute mess of you last night so…” Tony grins as he trails a hand down Steve’s stomach, which makes Steve’s muscles involuntarily twitch under the delicate graze of Tony’s fingers. “I’d recommend letting go of this crazy leaving idea and taking me up on that offer of a shower.”

Steve casts a wary glance back over his shoulder at Bruce. They hadn’t discussed this last night and he feels strange about doing anything with Tony alone. Just having the conversation feels like he’s breaking some kind of unspoken agreement. 

“I promise you, Cap, he won’t mind.”

“You sure?” He can’t imagine Tony would lie about this, because Bruce is one of the few things in Tony’s life that Tony tries not to treat as recklessly as he does himself. 

“100%. He’s not a morning person in the slightest – needs awhile to acclimate when he first gets up, better off leaving him to his own devices. He needs his meditation to get his head screwed on right." Tony must sense his stubbornly persistent unease because he leans forward and kisses him again, sweetly this time. Tony taps Steve's chin with his thumb as he draws back, smiling without guile. “Think in your day the AM Edition of Dr. Bruce Banner would’ve been referred to as quite the Grumpy Gus.”

Steve returns Tony’s smile with a weak one of his own, shifting on the bed as he considers following Tony’s lead here.

“Surprised you’re not one too, honestly – I was under the impression you and mornings didn’t get along either.”

“For some reason folks assume that, but no,” Tony shakes his head. “Besides, I’m a light sleeper, been in and out for awhile now.” He tugs the sheets from around Steve’s waist and attempts to pull him from bed again. Steve goes with it this time, but he still feels his face heat at being exposed. Tony chuckles, hands groping down Steve’s chest to his hips as Tony walks backward, guiding the both of them toward the bathroom. “It’s ridiculous that you’re blushing. I love it; it’s fucking adorable. You realize that the things we did last night should put us totally passed blushing territory, right?” The hungry look that Tony gives him is too heated and honestly _wanting_ to be categorized as a leer. “The places on your body that I put my mouth…”

“Tony…” Steve doesn’t really have an adequate answer besides blushing _more_ , but it doesn’t matter because Tony is pressing him back against the bathroom door. Tony moves to kiss him again but stops, seeming to think better of it. He unceremoniously drops to his knees. 

Steve barely has time to process the sudden change in Tony’s position; Tony’s mouth is already on him before anything else can register. The back of his head connects with the heavy wooden door as his body jolts in pleasurable surprise at the sensation of Tony's tongue eagerly licking up his entire length. He can’t stop himself from reaching out and grabbing Tony’s shoulder, _hard_ , though he doesn’t know if he’s trying to push Tony away or urge him on. 

“Oh…oh, Tony…” It’s intense, the blood rushing downward through his body quickly enough to leave him spinning. Tony pulls back, one hand closing around his length, holding him at an angle that makes it easy for him to tongue the head. 

“Yeah, that is just as awesome as it was last night,” Tony comments, looking up as he strokes and pumps, his gaze trained on Steve’s face. Steve tries to hold the look; it’s a dare of some kind but he doesn’t know to do what. Maybe to just stand there and take this, let Tony bring him off with little to no preamble, like this is a normal, every morning occurrence. 

The fact that it _could_ be an everyday kind of thing, that maybe Tony and Bruce really meant it when they’d said they hadn’t wanted this to be a singular experience…

His cock swells against Tony’s palm, the thin skin flushing and purpling as his girth expands. The first time he’d gotten hard after the serum, he’d actually been a little frightened by the size of it, sure that any woman would find it startling. Tony seems only to appreciate it though, mouth falling slightly open as he rubs just below the sensitive head. The uncut skin pulls back, revealing the tip that’s already beginning to leak, a shiny, pearly white drop of liquid gathering at the slit. Steve bites his own lip hard to try and repress a shiver. He fails. 

He doesn’t really know how to handle this; it’s a situation he thought he’d considered carefully and thoroughly before entering into it but now that he’s here, in the middle of it, he can’t tell up from down. All he knows is that Tony is going to make him come and he wants nothing more than to let it happen. 

Tony, who’s talking now, saying dirty things that he’d never imagined someone, _anyone_ , would direct at him. He never expected to like it either. 

“Want me to suck you again, Cap? You want to fuck my mouth with your huge cock? Come down my throat?” Steve moans, hitches his hips. Tony inches closer, knees sliding roughly against the carpet. Tony shows no signs of discomfort though, and Steve can’t summon the will to tell him to stand up. “I’d let you. I want you to, want it any way you want to give it. Maybe you wanna lose it all over my face? Bet that’d make you blush for days, every time I lick my lips I’d make you think of it. Get you hard just by looking at you, and everyone would see, the entire team would know how much you want my talented tongue on your massive dick. Everyone would know that I’m fucking you and that you love it.” 

Tony didn’t talk like this to him last night, but now the words are tripping off his tongue with typical ease and speed and they’re making it difficult for Steve to think of anything besides _exactly_ what Tony’s so filthily describing. Tony keeps moving his hand in a steady rhythm but he doesn’t follow up on his questions, evidently waiting for Steve to actually answer. 

Steve groans shakily, not out of his mind enough to lose his self-consciousness and beg the way Tony wants him to, the shameless way he knows he was only hours before. But he’s helpless to stop his hips from thrusting, pushing his cock harder and faster into Tony’s grip.

He cards his fingers through Tony’s hair, the rich hue of it quite striking against his own pale skin. Steve loves the way both Bruce and Tony _look_ against his body - the contrast of color and shape, the ways they differ from him and are similar to each other…he just wants to study it. Wants to lay them out on the bed and draw them until he understands every line and shadow that constructs their form. And then have them come together just so he can watch them move, see the lines blur and shift. 

They’d felt so good last night, and Tony feels so good now…

“Want you,” Steve gasps and without warning, sinks down in front of Tony, pushing Tony’s touch away and wrapping his own hand around Tony’s wrist. The move catches Tony off guard so Steve easily presses Tony down to the carpet, pinning Tony’s arm to the floor and turning the situation to his advantage. 

“Hey now-“

“I want you, Tony.”

“You actually had me, cowboy, thought we were on track-“

“Want my mouth on you.” Steve hears himself say it before he realizes it’s the truth. He bends over Tony and kisses away his protests before sliding his lips down Tony’s chest, brushing over the beautiful blue of the arc reactor before he eagerly swallows down Tony’s thick cock. He’d touched both Bruce and Tony with his hands last night, let them both inside of him, but he hadn’t felt either of them throb against his tongue. It’s a heady sensation, having that weight and heat inside his mouth. He loves it.

Steve mimics what Tony did to him, trying to remember all the little things that drove him to the edge. His mental memory is pretty decent and his muscle memory even better, and that thankfully makes him an exceptionally quick learner. He figures that Tony probably does to others what he likes himself, things that he knows for a fact to feel good and that work. Tony’s all about experience, about trial and error, and finding the best, most effective ways to do everything. Steve suspects that sex is no different, and that Tony knows ways to fine tune a body just like he can fine tune a machine. 

“Oh fuck, you are _unreal._ ” Tony is panting already. When Steve manages to lift his gaze and look up the length of Tony’s body, the pure lust that darkens Tony’s eyes nearly makes him stutter in his movements, setting off his rhythm as his concentration breaks. Tony swears, pulsing once inside his mouth. The bitter taste of Tony leaking over his tongue makes Steve’s own dick drip over the carpet. 

They shouldn’t be doing this on the floor, he thinks absently. It isn’t right, but Steve can’t stop. He’s greedy for it in a way he almost can’t believe. He’s always been so against letting anyone dominate him, obstinate in the face of any force that tried to overtake him. Sure, in a sense he now has Tony at his mercy but he’s never felt so out of control, so completely under the sway of someone else. 

He wishes Bruce would wake up and see this. He wishes Bruce would come over here and take him from behind, fill him up and move hard as he swallows Tony down. He wants every dangerous doubt and worrying thought driven out of his brain by the force of their desire. He wants to feel like he did last night, pushed to the point where all he could consider is who would touch him next and all he cared about was their hands and their mouths and the way their bodies fit against and inside of his. 

Tony’s hands are in his hair now, gripping just this side of too hard, and it feels fantastic. He’s holding back; Steve can feel the tension coiling in Tony’s body as he tries to resist. He doesn’t know how to tell Tony it’s okay without pulling off and actually speaking, so he just moans and swallows and sucks harder. The fact that he doesn’t need to breathe nearly as often as Tony and Bruce do is a distinct advantage that even someone as inexperienced as he can make good use of. 

“Fuck, baby, so amazing…” Tony calling him that sends a surge of arousal through his entire body, same way it did when he used the endearment last night. It’s something that’s just theirs, already, and Steve’s addicted to hearing it. It makes him feel less like a third wheel, a one-time featured player, like maybe he could be on equal ground in this with both Bruce and Tony. He hasn’t found that with Bruce yet though, and even Tony’s whispered _baby_ guarantees nothing. 

Steve closes his eyes more tightly and blocks out those unsettling thoughts, lightly grazing his teeth against the head of Tony’s cock as he nearly draws off, pausing for only a moment before taking him back in. One of his hands reaches up to lay flat on Tony’s stomach, feeling the rapid in-out of Tony’s breathing underneath his palm, fingers brushing the bottom rim of the arc reactor. He moves his other hand carefully around Tony’s balls, cupping them as they contract, pulling tighter up against his body. 

Tony’s cries grow increasingly louder and his thrusts become erratic, his breath coming in sharp gasps. Steve braces himself to swallow it all down and holds fast when Tony groans out a broken warning and desperately pushes at his shoulders. 

“Oh, hell." Tony nearly sobs when he realizes what Steve plans to do. And then he comes. And comes. And comes, filling Steve’s mouth with so much, so fast, that he can’t swallow it quickly enough. He feels it spill and drip down his chin the same time as it coats the back of his throat. 

This time yesterday morning he was eating a bowl of granola alone in the kitchen, contemplating Bruce and Tony’s offer, and now here he is, blowing Tony on his bedroom floor, come on his tongue and on his face. 

He surges upward and kisses Tony’s open mouth, deep and dirty and hard. Tony licks inside, surely tasting himself all over. Steve realizes hazily that sometime in the midst of thoroughly pleasuring Tony, he had come himself; he can feel the mess sticky over his stomach and thighs as he presses his body against Tony’s. It hardly seems to have mattered, because he’s as hard again as if he’d never come at all. 

“You…” Tony starts, trying to catch his breath as they finally break apart. “You are disturbingly good at that.”

Steve lies down, or more like collapses, next to Tony, his body finally starting to feel the effects of the slight lack of oxygen. 

“I know.” Steve admits in amazement. He’s not being immodest; he’s genuinely flummoxed by how incredibly _sexual_ he feels right now. He never thought of himself as this type of person. Maybe it’s because he never let himself entertain the idea much, maybe for fear of wanting something he thought he could never have or maybe because it once felt so wrong to dwell on such things. Even after the serum he never could quite shake the feeling that even with the right partner, sex would be sedate and careful; about her first and him a distant second; amazing but not _fun_ , and certainly not as wanton as he’d just let himself be. But now it’s as if something pent up has been let loose and he has no hope to re-contain it. 

He laughs a little at himself.

“Didn’t quite imagine taking to this so easily or enjoying it quite this much.”

Tony laughs too, turning on his side and propping himself up on one elbow so he can look down at Steve. 

“Well Lord knows I enjoyed it. Hell, Steve. My god.”

"That was quite the scene to wake up to,” Bruce interrupts, and both Steve and Tony lift their heads groggily and look toward the bed. Bruce is sitting on the edge of the mattress, his hair still sleep-mussed and his breathing a bit haggard. He rises and moves toward them. Bruce’s steps seem shaky and Steve can see that the dark hair on his stomach and chest are splattered and shining wet with the evidence of his own orgasm, his cock still half-hard between his legs. 

Bruce had been watching, pleasuring himself to the sight of the two of them together without him. Steve hadn’t even been aware Bruce had awoken. If only he’d come closer and interrupted much earlier. 

“Apparently Steve’s really into morning sex. Make a note in the file,” Tony announces as Bruce ambles passed them. Tony reaches out and trails a hand down Bruce’s calf as he walks around where they’re sprawled on the floor in order to get to the bathroom. 

Tony then sits up and looks down at Steve again. He trails his thumb over Steve’s bottom lip and brushes away the faint trail of come still left behind on Steve’s chin. He brings it back to his own lips; Steve follows the movement intently. He wants Tony all over again, immediately. 

Especially when Tony looks down his messy body, his unflagging erection, and desire flares in those dark brown eyes with renewed heat. 

“Now you _really_ need a shower, Cap.” Tony glances toward the bathroom, only two steps away, and then flops back down with an overdramatic sigh. “Good god, it’s too far away.” Bruce leans in the doorway and looks down at them with amusement as he slowly brushes his teeth. 

“So you’re going to stay on the floor all day?”

“Well this one sucked my brain out through my dick, I’m incapable of movement,” Tony retorts, throwing a careless arm over Steve’s chest. “You should just come down here with us.”

Bruce raises one eyebrow at them, the movement of his toothbrush stilling.

“You should.” Steve agrees. Bruce shakes his head, glancing down at his own chest.

“I think I heard one of the two of you mention, uh, a shower? I’m a little disgusting and you two are even worse.”

Tony moves his body to press against Steve’s side, propping his chin up on Steve’s shoulder. Steve watches as Tony runs a finger through the pools of come on his stomach. He idly traces an indecipherable pattern through it before opting to splay his fingers out wide, fanning through the mess and rubbing it into Steve’s still too-warm skin. 

“I see nothing wrong with turning Cap into a total disaster,” Tony comments after a moment, casting a sideways look at Bruce that pretty much dares him to find fault with the sight laid out in front of him. “I stand by my work here.”

“From where I was sitting, Tony, you didn’t seem to be doing any work,” Bruce observes dryly.

“You try holding out as long as I did and you might change your tune about that, Banner.” Tony smirks, his hand sliding to massage Steve’s inner thighs, moving slowly back up on one side before switching to the other. Steve shuts his eyes for a moment, trying not to let Tony’s ministrations get the better of him.

When he opens them, he makes the mistake of seeking out Bruce instead of Tony, thinking that will be safer. He finds the other man gazing at him, pupils dilated, his toothbrush still in his mouth and his hand unmoving. Bruce stopped mid-action to stare, almost like he’d forgotten what he was doing or lost all sense of motor coordination. 

Tony’s dexterous fingers are playing at his entrance now, deft and teasing, and for a second Steve shifts down into the touch, begging Tony to do it, to breach him and fuck him with his hand. Then the realization washes over him that that’s not exactly what he wants. 

“Would you let me…oh, unnnhhh…” Steve grunts, losing his train of thought as Tony’s fingers follow through on their promise. 

“Let you what?” Bruce prompts, taking the toothbrush from his mouth finally and taking a step forward. Tony strokes that perfect spot inside him and he has to close his eyes yet again, shutting off one sense because taking it all in five different ways is simply too much. 

“Want to do to you…what you did to me.” Steve nearly asks Tony to stop because he can’t think straight like this, but he doesn’t have to. Tony’s hand stutters and then his movements cease. He can hear both Tony and Bruce breathing heavily, feel Tony’s chest moving with each inhale and exhale. It’s clear they understood what he meant but they don’t reply. He forces himself to take a deep breath and say it clearly, knowing from last night that Bruce wants – needs – that from him. “I want to be inside you. I want to...to fuck you.” 

But still neither of them reply. He hears the sink faucet turn on, water blasting hard, and the clink of a toothbrush being deposited back into its stainless steel holder. Tony’s hand withdraws from his body and Steve shudders at the loss. He’s empty and cold without Tony’s touch. 

“Is that not okay?” Steve opens his eyes to look at Tony, his worry rising. Bruce is in the bathroom, facing away, and Tony is watching him with an indecipherable expression on his face. Steve looks back and forth between them, trying desperately to get a read on what he’s just done. The heady, hazy drift of arousal dissipates abruptly and dismay sends him crashing back down. He starts to sit up, drawing his legs in close, feeling all too exposed and wanting to disappear. “I’m sorry. We don’t…I don’t…it’s not anything that I have to –”

“Don’t.” Tony sets a hand on his knee, his voice serious. “Lay back down.”

Steve stares at him for a moment before complying. He’s terribly confused, especially when Tony reaches to run a hand gently through his hair.

“Which one of us do you mean?” Bruce asks, turning back to take his place in the doorway again. 

“I…both of you. Either of you. I don’t know.” That horrible anxiety he expected to feel last night is suddenly here and he wonders if he’s made a mistake by doing this. This isn’t really him, and he should’ve known better than to think otherwise. He lifts his arm to cover his face, needing a moment to gather himself.

“Steve.” Bruce interrupts his thoughts. Tony pulls Steve’s arm away from his face, running his touch from his bicep down to his forearm before tangling their fingers together. Steve dares to look as Tony kisses his knuckles, surprisingly sweet. 

Feeling more courageous with Tony’s encouragement, he looks to Bruce. 

Bruce has joined them on the floor now, kneeling by Steve’s feet. His hands are so much smoother and softer than Tony’s but just as gentle, fingers splayed wide over his calves as he tries to stop Steve from folding in on himself. Bruce smiles carefully, like he’s not sure he’s getting it exactly right. 

“I’m sorry, Steve. You just…caught off us off guard. We didn’t think…”

“What Bruce means to say is that you’re blowing our minds.” Tony grins against Steve’s hand before pulling it away from his lips. He bends and flexes their fingers together like he’s studying the shape and feel and size of Steve’s grip. “Keep on doing it, I’m _really_ enjoying it.”

“It’s okay if I crossed some kind of line.” Steve has re-grouped enough now to meet this head on. There are boundaries between where he is and Tony and Bruce’s actual relationship, and if he’s gone too far he needs to retreat and take some kind of responsibility for his actions. “You should tell me. I can handle it.”

“There aren’t any lines to be crossed here, Steve. There are no road maps, no rules.”

“You know how I hate rules,” Tony chimes in.

“We’re making this up as we go.”

“But you said…you had talked about this.”

“Oh, you figured we had parameters? Some kind of theoretical framework, an outline?” Tony chuckles. “Cap, when we said we talked about this, we meant things like ‘How many times do you think he can come in one night?’ and ‘Do you think the serum enhanced the size of his cock?’”

“Not our most intelligent conversations.” Bruce actually blushes a little, ducking his head and rubbing the back of his neck. Steve smiles at the sight of him, and just like that the tension is broken and he feels his whole body relax again. 

“So.” Tony quirks an eyebrow at Steve and slides his free hand down the length of his body to wrap around his softening erection. Tony holds his gaze with a teasing smirk as he strokes and it takes Steve a moment to register that Tony’s waiting for him to say something. 

“What?”

“ _Is_ this god-given or man-made?” Tony tightens his grip just a little, pumping harder. Tony shouldn’t do things like that and expect him to answer questions. “C’mon, Cap, guys were guys even in the 40s, don’t tell me no one checked.”

“It’s…" He pauses, embarrassed. "It's maybe an inch and a half, two inches more…"

"That's it?" Tony is slightly shocked and Bruce makes a small noise of surprise. "Then you were, uh, big for a little guy."

Steve knows he's blushing again. He glances down to where Tony's hand is still moving between his legs. 

"Honestly, it, uh, feels and looks more different than a couple inches to me. Seems like too much sometimes,” he admits, wondering all over again if maybe it is in fact too much, if Tony and Bruce were truly caught off guard because they can’t imagine Steve pushing inside of either of their bodies.

“It’s not too much,” Tony replies, his finger tracing up the vein on the underside of Steve’s cock. His touch is careful and slow, like he's considering something. “But to bring us back to Bruce’s question – which one of us did you mean? I don’t usually play catcher but in this case I’m totally up for it.”

“So that’s how it…I mean…so you’re usually…?” Steve looks to Bruce, who nods. 

“Neither of us is really all that firm on positions, but yeah, that’s typically how it goes.” Bruce’s touch has traveled higher up his legs now; he’s half leaning over his body in order to caress his hips. “But if you want Tony, you should-“

“When I asked, I meant you, but that’s not…” Steve blurts quickly, not wanting Bruce to think this has all been about Tony. It’s not. He _had_ been asking Bruce, at that moment. “It doesn’t have to be. It’s just…that’s what I…when I said it.”

Bruce leans forward and kisses him then, partially, Steve thinks, just to keep him from rambling on. But the kiss is too soft to be silencing. It’s more an assurance that he is understood and he doesn’t have to keep explaining himself.

Bruce tastes like cool like peppermint, smells of smoky sandalwood, like the incense he burns in his own quarters. The scent hangs on him now like it’s part of his skin, the same way that the slightly bitter tang of metal seems a part of Tony. 

Tony dips his head to whisper something into Bruce’s ear, something that makes Bruce moan against Steve’s lips. The vibration of it makes Steve answer in return, opening his mouth wider and drawing Bruce’s tongue in along his. Bruce tilts his head to go even deeper, moving to straddle his waist. 

Steve’s content to do this as long as Bruce wants, knowing neither Bruce nor Tony can recuperate quite as fast as he can. He’s willing to bide his time and let the insistent throb of his arousal dull into the background. His hands roam over Bruce’s body; everything about him just a bit softer than Tony, more open and easier to understand. 

They’re both emotionally and mentally guarded men, and Steve thinks that’s maybe why they found one another, why they work so well together. They can enjoy the physical without breaking each other’s walls down, since both of them respect what it’s like to need those barriers and leave them unchallenged in the bedroom. 

Tony’s walls may be cracked in places but they’re built high, they’re built solid, and they’re built thick. Bruce’s walls are far less sturdy, bending and dipping and letting things spill out, constantly shifting slippery like liquid. But where Tony’s defenses are evident to anyone who bothers to look, a man with armor even when he’s not in his suit, Bruce’s are practically invisible. It’s not until they’re broken down and everything’s loose that anyone even realizes Bruce had been hiding anything at all. 

Steve thinks maybe this will be their thing, his and Bruce’s. That he can hold Bruce together for a while and give him a break. There’s a way that the tension unspools underneath his hands that feels so raw and intimate, like his touch is melting Bruce’s body into his own.

As Bruce slides over and against him, Steve vaguely feels Tony drifting away and then drifting back. Tony’s lips brush his ear, his teeth gently teasing over the lobe for a moment before he finally speaks.

“I want you to suck him while I get him ready for you. You wanna do that, baby?” Tony whispers, hand cupping Steve’s chin and pulling his face away from Bruce’s searching mouth. Tony looks wild, his eyes wide and dark and his hair a mess. He pushes his thumb against Steve’s swollen bottom lip and Steve bites it gently, laves it with his tongue. 

Tony stares at him, completely silent. Bruce is quiet too, his breathing too carefully measured as he watches them watch each other. Tony blinks like he’d completely forgotten himself for a moment. He shakes his head and tears himself away, reaching for something just out of Steve’s line of sight. Steve moves when Tony prompts him, letting a soft pillow be placed underneath his head. 

Tony brushes a hand over Bruce’s hip and then closes the space between them, kissing him soundly. 

“Let me know when you’re close,” Tony murmurs as he urges Bruce closer to Steve’s mouth, Bruce straddling Steve’s broad shoulders. It’s possibly a little embarrassing how eagerly Steve parts his lips as Bruce guides himself inside. 

He’s not hard, but not quite soft, and Steve takes his time working him up to the edge. He’s more in control now than he’d been with Tony and he uses the clarity to thoroughly explore how Bruce reacts to his tongue, his lips, his teeth, his throat, his hands. Though he’s incredibly turned on, he likes being able to think about what he’s doing. He thought he’d been doing that with Tony, but he realizes now most of that was instinctual and slapdash. 

Tony positions himself behind Bruce and Steve hears rather than sees Tony slick his hand, slide his fingers into Bruce’s body. Bruce sighs and pushes further into Steve’s mouth, hips thrusting forward. 

“Sorry…” He mumbles, hands going to either side of Steve’s head cradling his face gently and trying to ease his cock from Steve’s throat. 

“He can take it,” Tony reassures Bruce, and Steve opens his eyes and looks up at them both, finds Tony smiling wickedly and winking at him. Then Tony does something with his hand that sends Bruce keening. The taste of pre-come finally spills over Steve’s tongue, Bruce’s length swelling to full hardness. 

“God…this isn’t going to take long,” Bruce gasps, sounding surprised. 

“He’s ridiculous, I told you,” Tony responds with a breathless laugh. Tony reaches around Bruce and runs a hand roughly through Steve’s hair; Steve leans into it. “Fucking makes your head spin.”

“Beautiful,” Bruce mimics Tony’s motion but leaves his hand there, fisting his fingers in Steve’s short locks. Steve swallows around his length and feels Bruce actually shudder and swear. He lets go of Steve’s hair and grabs the base of his cock. “Okay, yeah, that’s… _fuck_.” 

Steve takes the hint and draws off slowly, letting Bruce go little by little, making Bruce shiver again as he realizes just how much Steve had taken in. Steve wipes his wet lips with the back of his hand and drops his head back against the pillow as he looks up at them both, catching his breath.

Tony puts his hands on Bruce’s hips to steady him. 

“You’re not quite there yet,” Tony warns, and Bruce nods, sagging back against Tony for a moment and closing his eyes. 

“Yeah, I know, I just…go with me on this one, Tony.” Bruce taps Tony’s thigh and starts to move. Tony has no choice but to climb off as Bruce does the same, and then resituates himself so he’s straddling Steve again, this time facing the other way. 

“You are officially smarter than me,” Tony declares. Steve’s not all that sure what’s going on but Bruce’s cock is dripping against his face and Bruce is pushing it toward his lips, so Steve takes hold and guides it the rest of the way back in. 

Bruce rests his hands on Steve’s stomach, leaning his weight forward as he urges his hips gently toward Steve’s face. Steve can’t see anything like this but he can hear and feel Bruce breathing, harsh sharp pants like he’s trying to get a hold of himself.

And then Bruce’s mouth is on him again and his fingers are pushing into his body and Steve has no choice but to arch into it, spread his legs wider, and groan loudly enough to startle himself. The pleasure is so overwhelming it’s shocking. 

“ _I can’t believe this is my life_.” Tony says, actually sounding stunned for the first time since Steve’s met him. Steve can’t even feel triumphant – all he can do is agree with the sentiment. He’d been dead set against Tony having JARVIS record their night together, but now he almost hopes Tony disregarded his wishes and did it anyway. He might not believe this ever happened without concrete evidence. 

Soon Bruce is rocking into his mouth and back against Tony’s fingers and Steve can only make helpless, ridiculous noises, too turned on to care. Steve puts his hands loosely at Bruce’s waist and just feels the thrusting rhythm, going with it and letting himself be used. At this point, actually getting inside of Bruce is going to seem like an afterthought. He can’t imagine feeling anything better than this. 

Turns out, he’s wrong. So, so wrong.

He discovers that the instant that Bruce is around his length, hot and wet and tight, so _tight_ , and Tony, god, how did he not know this is what they had in mind, Tony is thrusting into _him_. Steve can’t believe he’s actually making love to two people at the same time; Bruce rides him, practically bouncing on his cock as Tony pounds inside. He’s fully and completely lost in the both of them, taking and being taken and it’s very nearly too much. 

Steve wants to focus on them, make this last, but he supposes that this is exactly what they meant last night by saying this is all about him. He manages to get a hand on Bruce, swollen and slick under his palm, but he barely has the coordination to move. Tony wraps his own hand around Steve’s and they stroke Bruce together, the pace brutal. Tony is deep inside him, the sound of skin slapping skin echoing in the room each time Tony thrusts in, slamming into his willing body. Steve is helpless against them, and he’s coming faster and harder than he ever believed possible. 

“Steve…!” Bruce cries out sharply as Steve empties inside of him, the sounds of their bodies sliding together getting wetter and louder as Steve thrusts and thrusts, his orgasm seemingly never-ending. Bruce comes violently, reaching back to hold onto Tony’s body as his come streaks Steve’s chest over and over again, splattering up to his throat and chin. 

Bruce collapses forward as he finishes and Steve holds onto him, feeling Bruce shaking in his embrace as he slips from inside Bruce’s body.

“I got you,” Steve manages to whisper between gasps of air, pulling Bruce tighter as Tony puts his now free hands on Steve’s inner thighs and spreads him wider, then slides underneath him to grip his ass, tilt him slightly upward. 

“Oh _god_!” Steve can’t help but take the Lord’s name in vain as Tony repeatedly pounds against him, hitting just the right place to send something electric jolting through his whole body. His eyes roll back in his head, groaning, and as he throws his head back against the pillow, Bruce kisses the exposed arch of his neck. Tony comes, an explosion of wet heat inside, and Steve feels himself attempt to echo Tony, weak spurts that join the sticky mess Bruce made all over his skin.

Despite this Tony strokes him through it, trying to coax more out of him.

“Love coming inside you, baby. So amazing, god, and your cock, it just…” Tony pumps him one more time, thumb dragging against the head, and Steve moans in pleasure-pain as his body valiantly attempts to give Tony another go. His dick is pumped nearly dry and aching. Tony lets him go with a noise of complete satisfaction. 

Tony pulls out, leaving him wet and loose and empty. Tony gently eases Steve back to the carpet, lets his legs relax. He shifts to the side, pausing before he lies down to circle a finger around Bruce’s entrance. He pushes in gently, just a little, and Bruce whimpers. 

“I wish I could lick him out of you, Bruce. He tastes so good.” 

Bruce makes a small noise of protest, shifting to lay next to Steve’s side rather than on top of him, pulling away from Tony’s reach. 

“Next time,” Bruce mumbles against Steve’s chest. “I literally cannot take any more, I may be rendered entirely useless.”

“Tony, c’mere.” Steve barely recognizes his own voice. He sounds utterly wrecked, deep and raspy. Tony sinks bonelessly down to the floor beside him. He lolls his head onto Steve’s shoulder and lazily presses a sloppy kiss to his used lips. 

“You’re never leaving us,” Tony says. “Not after that.”

Steve doesn’t know how to reply. He wants to agree wholeheartedly. 

“Best substitution for meditation I’ve ever found,” Bruce adds, without lifting his head. “You can wake us up anytime, Steve.”

Both Bruce and Tony’s eyes are drifting closed. Steve looks them both over, considering, and reaches down to gingerly touch his messy skin. 

“I think now might be a good time for that shower,” he suggests, gently prodding Bruce in the shoulder. Bruce grunts in disinterest.

“Shut up and let us sleep,” Tony mutters, putting his hand over Steve’s mouth. Steve can’t help but smile against Tony’s palm. He lifts it from his face, folding Tony’s fingers against his own and brushing a kiss over them. 

Then he settles in, knowing he probably won’t sleep but content to be where he is. He supposes he’s going to have to get used to this. 

He doesn’t mind one bit.


End file.
